The two brother generally wear . . . . . . clothes.

The question asks about the correct possessive pronoun to use with "two brothers" and the clothing they wear.

First, let's define possessive pronouns. These are pronouns that show ownership or possession. Examples include mine, yours, his, hers, its, ours, theirs. The question tests our understanding of possessive pronouns which also applies to phrases like "one another's" and "each other's".

Option A: their
"Their" is a plural possessive pronoun. It correctly shows possession, indicating that the clothes belong to the two brothers collectively. However, it doesn't specify whether they share clothes or wear their own.

Option B: one another’s
"One another's" implies that the brothers are wearing each other's clothes. This is a possible scenario, but not the most common or natural interpretation of how two brothers might dress.

Option C: each other
"Each other" is a reciprocal pronoun, indicating a mutual action or relationship between two or more people. While it shows interaction, it doesn't denote possession. It's incorrect because it doesn't show who owns the clothes.

Option D: each other’s
"Each other's" is the correct answer. It's the possessive form of "each other," clearly showing that the two brothers wear clothes that belong to each other. This suggests a shared wardrobe or a habit of borrowing clothes from one another. This is a perfectly grammatical and understandable scenario.

Therefore, the best answer is Option D: each other’s because it accurately and concisely reflects the shared or reciprocal nature of clothing ownership between two brothers.